This invention relates to the casting of steel ingots, more particularly to such casting in which "open bottom" molds are supported by flat slabs, called "stools", usually of cast iron. These molds conventionally are rectangular and of decreasing cross-section from bottom to top to facilitate removal of the ingots from the molds when they have cooled sufficiently.
Due to irregularities in the surface of the stools and in the bottom rim of the molds arising in the manufacture as well as caused by erosion in the use of these elements, the joint between the rim and the stool is not tight. To prevent flow of molten metal through this space, with consequent loss of metal poured if the space is great, or the development of "stickers" if the space is minor, various expedients have been suggested or used to seal the joint.
One such means is the use of a sealant in a deformable tubular container covered with cardboard. The container may be designed to rupture in use. Such a means is disclosed in U.S. Pat. No. 4,369,830. An expanded metal seal is disclosed in U.S. Pat. No. 4,135,589. Tubular sealing means are shown in valves in U.S. Pat. No. 1,043,065.